CHIN MUSIC: St. John’s Malik Boothe takes it on the chin, literally, during this run-in with Syracuse’s Scoop Jardine during the Johnnies’ 79-73 loss yesterday in the Big East quarterfinals at the Garden.Charles Wenzelberg/New York Post

As St. John’s trainer Ron Linfonte sprinted across the court about six minutes into yesterday’s game, he had one thought:

“In 30 years of treating St. John’s athletes, D.J. Kennedy is one of the toughest kids I’ve ever had.”

When Linfonte got to the fallen senior, who was clutching his right knee, he heard words that will send shivers through every St. John’s fan who has embraced this team, a team that will be cherished as the one that restored the Red Storm’s pride.

St. John’s lost more than its Big East quarterfinal to Syracuse, 79-73, yesterday. The Red Storm lost one of their key players, and their senior leader, for the NCAA tournament.

An MRI exam performed last night at the Hospital for Special Surgery in Manhattan revealed that Kennedy suffered a torn ACL when he came to a jump stop and the knee buckled.

He finishes his St. John’s career with 1,493 points, one of only three players (Malik Sealy and George Johnson) to score 1,450 points, grab 750 rebounds and make 150 steals.

“I’ve wanted to play in the NCAA tournament since I picked up a basketball in grade school, and this is a real blow,” Kennedy said.

It’s a helluva blow — four years of blood, sweat and tears and, now Kennedy doesn’t get to Dance.

“There’s nothing that you can say to a competitive athlete who is wounded in the line of duty that’s going to be able to put a positive spin on it,” St. John’s coach Steve Lavin said. “All you can do is try to provide perspective, which is, ‘It sucks and you’ll be back.’ “

Amazingly, Kennedy provided one last spark — an emotional one — even as he lay on the court knowing, as he told Lavin, “It’s bad.”

The Red Storm had fallen behind the Orange 12-5, and it was 14-5 when Kennedy was helped to the locker room. St. John’s responded with a 17-6 run to take a 22-20 lead. The battle lines were drawn:

The bigger, deeper Orange kept working inside. The smaller, quicker Red Storm kept slashing the lane and crashing the boards.

With 12 minutes, left the Orange had overcome a 37-32 halftime deficit to take a 52-51 lead. Dwight Hardy and Syracuse’s Brandon Triche (22 points each) shot it out for a few minutes, but at the end, a Rick Jackson offensive rebound was converted by Kris Joseph into a basket and a 72-68 lead with 1:16 left.

The prior time the Orange and Huskies met in a league tourney semifinal was 2009. That game went six overtimes, with Syracuse winning 127-117. Bring your pillows and blankets.

And bring some Kleenex for Kennedy and St. John’s (21-11), which could have its NCAA tournament seed downgraded by Kennedy’s injury. A serious injury to a key play is considered by the selection committee.

“Look at Georgetown,” said Syracuse coach Jim Boeheim, whose team lost center Arinze Onuaku to a quad injury late last season.

“They haven’t won a game since Chris Wright went down. They went from a top 10 team … I don’t know if they lost four in a row or what, [but] they certainly haven’t done a lot.

“You can’t absorb a loss like that, especially if you have three keys. It’s difficult to lose a guy like that, no question about it.”

Lavin tried to remain upbeat.

“Our approach this entire year has been the strength is in the pack,” he said.